He's like the super-talented child that dominates against amateurs without having to try because of his natural physical gifts, but as soon as he comes up against professionals, that lack of heart and work-ethic make him mediocre as shit.
Ogbonna dominated Serie B, his physical gifts ensured that he would have an easy time against the second rate competition there, but as soon as he arrived in Serie A, against top class players he's exposed for being lazy and lacking in heart, and his physical gifts mean fuck all.